Cementing collar for drilling with casing



J. E. ECKEL CEMENT'ING COLLAR FOR DRILLING WITH CASING B ALLSTOPS Fig. 2

John E.Ecke| Inventor A'flornev Filed. Oct. 11, 1954 United States Patent CEMENTING COLLAR FQR DRILLING WITH CASING John E. Eckel, Tulsa, Okla, assignor, by mesne assignments, to Jersey Production Research Company Application October 11, 1954, Serial No. 461,310 2 Claims. (Cl. 166-136) This invention concerns a novel apparatus for use in drilling bore holes by the so-called drilling with casing technique. This invention concerns means to cement the casing in a bore hole in order to complete a well without necessity for retracting the casing from the bore hole after the drilling operation. The invention includes a wire line cementing apparatus which may be lowered through the casing and locked at the bottom thereof. This .apparatus is equipped with suitable packing means so that cement can be pumped down the casing and will be directed by the apparatus so as to properly cement the casing in the bore hole. Thereafter the apparatus may be retrieved from the casing or alternatively can simply be drilled out of the casing and the well can be completed in the normal manner.

At the present time, a great deal of effort is being directed to provision of a suitable drilling with casing technique for use in the drilling of petroleum wells. In the normal rotary drilling procedure, the bore hole is cut into the earth by means of a drill bit suspended on and operated by a string of relatively small internal diameter pipe in the bore hole. As the bits become worn, it is necessary to withdraw the entire drill string from the bore hole to replace the bits. Similarly it is necessary to Withdraw the drill string from the bore hole in order to conduct other operations and in order to complete the bore hole by placing a permanent casing in the hole when drilling has been completed.

As opposed to this, in a drilling with casing technique the objective is to use the final bore hole casing in all steps of the operation including drilling and well completion. Thus, in drilling with casing, so-called retractable drill bits are employed which can be lowered through the casing on a wire line to be locked at the lower termination of the casing for drilling. Bits may be replaced or removed through the casing by suitable retrieving devices. Retractable bits of this type are shown in the Sewell Patents 2,330,083 and 2,338,670, for example.

The present invention is concerned with a technique of well completion after a bore hole has been drilled by the drilling with casing technique. Thus, when drilling has been completed, it is necessary that cement be pumped into the bore hole in such a manner as to get back of (or around) the casing so as to completely seal the casing in the bore hole. New problems are involved in carrying out the cementing operation when the drilling has been completed by use of casing rather than the conventional drill pipe.

In accordance with this invention, when a bore hole has been drilled to a suitable depth by means of a retractable drill bit mounted in a casing, the retractable bit is withdrawn from the casing, and the apparatus of this invention is employed to cement the casing. The cementing apparatus constitutes a wire line supported arrangement adapted to be lowered down through the casing and to lock in a fixed position at the lower termination of the casing. It is necessary that the cementing apparatus be provided with means to lock its position in regard to either.

upward or downward movement relative to the casing. A central barrel of the cementing apparatus is employed to direct cement from the interior of the casing above the apparatus through the barrel so the cement can flow beneath and about the casing in the bore hole. Packing means are included about the barrel within the casing so that suitable pressure can be applied in pumping the cement through the apparatus so as to satisfactorily cement the casing. The apparatus of this invention is particularly adaptable for use in conjunction with the retractable bit arrangement of the co-pending application Ser. No. 268,894 of John E. Ortloif, filed January 29, 1952, now Patent No. 2,771,275 issued Nov. 20, 1956, and entitled, Hard Formation Retractable Drill Bit.

The nature of this invention may be fully understood from the following description when reference is made to the accompanying drawing which diagrammatically illustrates a preferred embodiment of the invention.

Figure 1 shows the apparatus in sectional elevation.

Figure 2 is a cross section taken on line II-II of Figure 1.

Referring to the drawing, the numeral 2 designates a casing which is run into the bore hole as drilling progresses. The lower end of casing 2 may be provided with threads permitting attachment to a collar element 1 which is designed and adapted both to support a retractable drill bit for use during drilling and to support the cementing apparatus of this invention. Collar 1 is provided with an upper groove 4 cut circumferentially around the inside of the collar and a lower groove 3 cut circumferentially around the lower portion of the inside of the collar. Grooves 3 and 4 respectively provide recesses in which latching means of a retractable drill bit may seat so as to lock the drill bit against both downward and upward movement with respect to the collar, groove 3 presenting an upward facing shoulder and groove 4 presenting a downward facing shoulder. It will be noted that groove 3 has an upward and inward taper and groove 4 has a downward and inward taper.

It is assumed that drilling has been completed and that the retractable drill bit has been withdrawn from the drill collar 1. The apparatus illustrated in the drawing is then lowered by means of a wire line into the casing to lock in drill collar 1 in the position shown.

The cementing apparatus illustrated comprises a sinker bar 11 having a conventional spearhead 10 adapted to be releasably supported by a wire line grip attachment. Sinker bar 11 is threaded to a sleeve 8 which extends downwardly in telescopic sliding relation with an inner barrel 7. Barrel 7 is provided with a number of upper latching dogs 13, preferably three in number, which can move outwardly through ports in sleeve 8 urged by means of the bowed springs 19 illustrated. A lower wall portion 17 fixed to the lower portion of the port in sleeve 8, associated with each of the latching dogs 13, extends upwardly from the port. In this arrangement when the weight of the apparatus is suspended on the spearhead It), sleeve 8 will be held in an uppermost position with respect to barrel 7 and lower wall 17 of the sleeve 8 below the ports will engage the latching dogs 13 and hold them in a retracted position.

Similar latching dogs identified by numeral 12 are fixed to the lower termination of the barrel 7; latching dogs 12 are again biased outwardly by means of the bowed springs 20 illustrated.

When the cementing apparatus shown is lowered into the casing, lower latching dogs 12 will slide along the casing in an unobstructed manner until these dogs reach the shoulder provided by the lower groove 3 in the collar 1. At this time the latching dogs will extend outwardly so as to lock the apparatus as regards further ing apparatus will be locked within the collar 1 withrespect to movement upwardly or downwardly in the collar.

A number of ports 14 are cut through sleeve 8 so that cement forced downwardly through the casing from the surface of the earth can pass into the interior of the apparatus through the ports. Flow of cement through ports 14 occurs because packer 1S seals the annulus between sleeve 8 and casing 2. Packer 15 may conveniently be askirt type elastic packer which may be reinforced with spring bands to maintain the configuration illustrated.

A second packing element identified by numeral 22 ispreferably positioned at the bottom of barrel 7 so as to seal the annulus between barrel 7 and the lower portion-of the collar 1, and thereby isolate the locking dog mechanisms from contact with cement. Packing element 22 may be of the nature indicated with respect to packing element 15 except that packer 22 will be of a character adapted to prevent flow of cement upwardly past the packer.

A third packing element indicated by numeral 16 is required to establish a fluid seal between barrel 7 and sleeve 8. Packing element 16 can constitute an O-ring or chevron cup type seal. Finally, a central check valve arrangement indicated by numeral 18 is positioned at the interior central portion of barrel 7. As illustrated, the check valve may constitute an orifice having a seat 23 against which a simple valve ball can seat. The ball is prevented from falling out of the valve arrangement by means of a spider arrangment below the ball provided with supporting lugs 24.

In using the apparatus described, cement pumped through the casing will pass through ports 14 to flow downwardly through check valve 18, which permits such flow in an unobstructed manner, and thence through barrel 7. The cement will then flow downwardly about the lower termination of collar 1 so that it can be forced upwardly behind collar 1 and casing 2 to suitably cement the casing in the bore hole. Flow of the cement in the course identified is maintained by virtue of the packers which have been described. The tendency for the cement to back flow after the pumps are stopped due to the high pressure of cement forced behind the casing, is prevented by means of check valve 18. This is neces sary to prevent back flow of the cement prior to its taking a permanent set.

As a practical matter, certain refinements of the general apparatus described should be appreciated. Preferably the interior of casing 2 above packer is of substantially greater diameter than the portion of the casing at which packer 15 is mounted to seat and seal. Similiarly the lower portion of collar 1 against which packer 22 is intended to seat and seal is preferably of substantially smaller diameter than any of the elements above this. As a result of this arrangement, the apparatus described can be lowered through the casing without obstruction on the part of the packers. It is also important to observe that the cementing apparatus described is preferably to be constructed of aluminum, bronze, magnesium alloy or other drillable material so that the cementing apparatus can be drilled from the casing in the event it becomes necessary. It is convenient that the sinker bar 11 be constructed of a drillable alloy which is lead filled for the same reason. Alternate construction may provide that the sinker bar be a permanent part of the wire line apparatus and that fishing head lii be attached directly to the sleeve 8 at the threaded portion 25. Thus, drilling of the sinker bar then would be positively eliminated.

These provisions are followed in the event that the cement apparatus cannot be removed from the casing after the cement has set. However, except for possible failure of the lower packing element 22 it is generally practical to recover thecementing apparatus by means of a wire line retrieving device after cementing has been completed. Thus, when an upward force is applied to spearhead 10, sleeve 8 will slide upwardly with respect to barrel 7 and lower Wall portions 17 will contact latching dogs 13 so as to move the dogs inwardly. Thereafter, except for resistance by the small amount of cement at the lower termination of the apparatus and above packer 15, it is possible to retrieve the apparatus from the casing without obstruction.

While the apparatus described is of particular application for use as described, the invention is also of value in-runnin'g in strings of casing after conventional operations where drilling with casing is not employed. In placing casing in a borehole, a float valve is normally attached to the bottom of the casing string to prevent mud in the hole from entering the casing. However, at shallow depths floating of the casing must be overcome by filling, the casing with drilling mud, delaying the running operation and consuming time and labor.

By applying the present invention to the conventional casing running operation, the float valve may be left out until needed, thus eliminating the time wasting filling up operation. When the depth is reached at which it is needed, it may be installed by the wire line method disclosed in the invention for the purpose of floating the casing and relieving weight from the hoist, as well as its final use of preventing back flow of cement as described.

What is claimed is:

1. An apparatus for cementing casing in a bore hole which comprises a collar member attachable to the lower end of the casing and provided with a first annular recess presenting a downward facing shoulder and having a downward and inward taper below said shoulder, said collar member also provided with a second annular recess spaced vertically below said recess presenting an upward facing shoulder and having an upward and inward taper above said upward facing shoulder, a sleeve member adapted to move within said casing and said collar member, a barrel member slidably fitted within said sleeve member, first extensible latching means pivotally mounted to said barrel member and adapted to engage said downward facing shoulder through ports provided within said sleeve member, second extensible latching means pivotally mounted on said barrel member vertically below said first latching means and said sleeve and adapted to engage said upward facing shoulder, resilient means urging each of said latching means into said recesses, a packer on the exteriorof said barrel member to seal the annular space between said barrel and said collar, a second packer positioned exterior of said sleeve to seal the annular space between said sleeve and said casing, means attached to said sleeve to retract said first latching means from said first recess upon upward movement of said sleeve'relative to said collar, and check valve means positioned interior of said barrel adapted to enable fluid to flow selectively downward therethrough.

2. A cementing apparatus for cementing casing in a borehole comprising, in combination, a collar member attachable to the lower end of the casing and provided with a first annular recess presenting a downward facing shoulder and having a downward and inward taper below said shoulder, and with a second annular recess spaced below said first recess, presenting an upward facing shoulder, and having an upward and inward taper above said upward facing shoulder, a cylindrical barrel member adapted to pass down through said easing into said collar member, first extensible latching means fixed to said barrel and adapted to engage the downward facing shoulder of saidfirst recess, second extensible latching means fixed to said barrel below said first latching means and adapted to engage the upward facing shoulder of said second recess, spring means urging each of said latching means into said recesses, packing means circumferentially positioned on the exterior of said barrel member both above and below said latching means to seal the annular space between said barrel member and said collar and to isolate said latching means from contact with cement, a check valve positioned in said barrel member adapted to permit flow of cement downwardly through the barrel member and to prevent flow of cement upwardly through the barrel member, and means for retracting said first latching means from said first recess whereby said barrel member may be retrieved through said casing.

References Cited in the file of this patent UNITED STATES PATENTS Crowell Feb. 7, Rohrbaugh July 5, Newton Apr. 11, Hammer May 30, Chappell Apr. 29, Miller Oct. 20, Miller Mar. 30, Fredd July 9, 

